Yeast viruses and their implications in fermented foods and beverages

The discovery that yeasts are natural hosts for viruses in the 70s marked the beginning of research into yeast virology and, particularly, the killer yeast system. These viral sequences encode host toxin secretion, modulating microbial communities, and ecosystem functions in fermentation processes. Wine is the most frequently studied fermented food for this topic, and the presence of dsRNA virus of the family Totiviridae , infecting mainly Saccharomyces spp., was initially associated with fermentation failure. After being better described, the possibility of the beneficial use of the ‘Killer yeast’ was raised, and food technologists started to develop robust strains to modulate final product quality. In addition, with the advancement of next-generation sequencing and food viromes studies, new viral groups and beneficial ecological functions have been revealed. This review addresses important topics on yeast virus and fermented foods, including diversity, ecology and applications, and a patent landscape and detection methods of the killer yeast system.